Field of the Invention
The disclosed information generally relates to a feeding device having a plurality of feeding ports through which to feed a recording material.
Description of the Related Art
Some conventional feeding devices each included in, for example, a copying machine or a printer are equipped with a lifter mechanism which uplifts sheets placed on a cassette. Such a feeding device is provided with a sheet surface sensor which detects that the sheets uplifted by the lifter mechanism have arrived at a sheet feeding position, and the lifter mechanism uplifts the sheets placed on the cassette until the result of detection by the sheet surface sensor changes. This allows the position of sheets to be kept almost constant and also allows a pick-up roller to stably feed a sheet at an optimal pressure. Furthermore, some sheet feeding ports other than cassettes include a manual feed tray. The manual feed tray is configured to allow a plurality of sheets to be placed thereon, and has a benefit in that various sizes of sheets are allowed to be fed without the user bothering to replace sheets placed on the cassette.
Japanese Patent Application Laid-Open No. 2009-256069 discusses a feeding device equipped with a cassette and a manual feed tray as a plurality of sheet feeding ports. In the feeding device discussed in Japanese Patent Application Laid-Open No. 2009-256069, the cassette and the manual feed tray are located very close to each other in vertical direction for the purpose of miniaturization, and the respective conveyance paths thereof join together at a position more upstream than a separation mechanism for sheets. In other words, the feeding device has such a configuration that a sheet fed from the manual feed tray is conveyed to a space between the uppermost sheet placed on the cassette and the pick-up roller.
Here, as mentioned above, the lifter mechanism needs to be equipped with the sheet surface sensor. Since the sheet surface sensor is located near the pick-up roller, in the case of the configuration discussed in Japanese Patent Application Laid-Open No. 2009-256069, the sheet surface sensor would react to a sheet fed from the manual feed tray. Accordingly, during a period when a sheet fed from the manual feed tray is passing a detecting position of the sheet surface sensor, the sheet surface sensor is not able to detect that the sheets placed on the cassette have arrived at the sheet feed position. Therefore, in a case where the user has performed an opening and closing operation on the cassette during a period when a plurality of sheets is being fed from the manual feed tray, a lift-up operation for raising the sheets placed on the cassette is not immediately started, but the lift-up operation is started after a sheet feeding operation from the manual feed tray is completed. However, in a case where an instruction to feed a sheet from the cassette immediately after the sheet feeding operation from the manual feed tray is completed has been issued, downtime due to the lift-up operation may be caused before an instruction for sheet feeding from the cassette is carried out.